Hurricane season 2015 starts today. Will it be slow?

The first of June means the first day of hurricane season – at least officially – in Mexico and the United States.

The season runs from June 1 to November 30, and this year’s names for storms are being recycled from 2009, which was a relatively quiet season.

So be on the lookout for Claudette and Danny, Joaquin and Kate, even Teresa and Victor if it’s a busy storm season.

Why even name the storms? The United Nations’ World Meteorological Organization approves the names by regions. But the storms are named to help increase public awareness, and provide quick, accurate information in warnings, especially when multiple storms are active.

Huracan Andres (Photo: lopezdoriga.com)

Nearly ten years after flooding during and after Hurricane Katrina devastated metro New Orleans and the Mississippi Gulf Coast, there have been dramatic improvements in forecasting the paths and landfalls of succeeding storms.

But as the 2015 hurricane season begins Monday, experts warn that efforts to forecast the intensity of hurricanes are still lagging behind, especially when a storm intensifies by more than one category in a few hours — a process called rapid intensification.

“On tracks, we’re definitely 20 to 25 percent better than we were in the Katrina timeframe,” said Frank Marks, director of NOAA’s Hurricane Research Division. “On intensity, we’ve moved the bar from no change in our forecasts to some change.”

The caveat comes as local and national officials urge residents not to get complacent by forecasts of a below-average hurricane season and by the lower risk of flooding during moderate storms thanks to improved levees.

“Low average doesn’t mean no pitches get thrown our way,” Kathryn Sullivan, administrator of the National Oceanic and Atmospheric Administration, said as she announced the season’s forecast Wednesday (May 27). “1992 was a below average season as well. Talk to folks of south Dade County (Fla.) how (Hurricane) Andrew affected them for decades after landfall.”

But it was Katrina, the nation’s costliest hurricane-related disaster, what prompted a shift in forecast research and a years-long effort to improve the accuracy of storm forecasting.

The track improvements allowed the National Hurricane Center to limit its warnings during last July’s Hurricane Arthur to the Outer Banks area of North Carolina, instead of including a broad area stretching from Georgia to Virginia, Marks said.

The result of such improvements meant that communities outside of the much smaller watch and warning areas could take advantage of Fourth of July weekend activities without ordering evacuations, he said.

In the past 10 years, the track error at landfall has dropped from about 175 miles in 2005 to just under 150 miles in 2014 for forecasts three days before landfall. The track error two days before landfall is down from about 125 miles in 2005 to about 100 miles. The 24-hour forecast error is down to about 50 miles, according to statistics discussed by the National Hurricane Center’s James Franklin at a conference in April.

The 2015 hurricane season will be less active than average according to Nation Hurricane Service and National Weather Service experts, but that didn’t stop local residents from stocking up on supplies. Many came into the Home Depot store in Uptown New Orleans to get items they may need should a storm system set its’ sights on the metro area.

Intensity errors actually have seen a sharp decrease over the past 10 years, from 20 percent error in wind speed to 10 percent. But Franklin warned that there were wild swings in the intensity errors during the past five years, and that environmental factors around storms in 2013 and 2014 may have affected the predictions.

Marks said researchers have used NOAA’s own computer forecasting model, called the Hurricane Weather Research and Forecast System, or HWRF, to work on the intensity forecasting problem by operating it on storms in the Pacific and Indian oceans.

“Unfortunately for the development of HWRF we haven’t had a lot of Atlantic storms recently,” Marks said. “But two years ago, the western Pacific had 27 storms and last year the eastern Pacific had 22 storms. So now we have a global database.”

The Hurricane Research Division’s scientists also have been partnering with their counterparts in Taiwan, India and Japan to develop the model globally.